1. Field of the Invention
The invention relates to a resistive memory technology, and more particularly relates to a writing method for a resistive memory cell and using the writing method for the resistive memory.
2. Description of Related Art
The resistive random-access memory (RRAM) is a new type of non-volatile memory which can use the changing of resistance state to memorize or to store numerical values. The resistive memory is excellently compatible with the logic manufacturing process, and has a fast write speed and a lower write voltage to meet the low power consumption requirement of the portable electronic products.
In the resistive memory, the three operations: forming operation, set operation, and reset operation are three important steps to ensure the electrical property and the data retention of the resistive memory cell. When performing the set/reset operation, the input voltage needs being progressively increased many times to finish the operation. However, when high input voltage is used to perform the set operation or the reset operation of the resistive memory cell, it may need decreasing the current which is originally corresponding to the high-current state of the resistive memory cell, or it may need increasing the current which is corresponding to the low-current state of the resistive memory cell, this phenomenon is called complementary switching manifestation. The complementary switching manifestation is a unique phenomenon in the field of resistive memory. In other words, an insufficient input voltage can cause the failure of the set operation and the reset operation, and an excessive operating voltage also generate a similar result. Therefore, how to prevent the input voltage in the process of progressively increasing from making the resistive memory cell generate the complementary switching manifestation because of the excessive voltage when performing the set operation and the reset operation is an important topic.